Portable crane



"" INVENTOR.

Zc zyzon J. J/mffcn BY ATTORN E? L. S. SHAFFER PORTABLE CRANE Filed July 31. 1922 2 Sheets-Sheet l Dec. 18, 1928.

'Dec. 18, 192a 1,696,174

' L. S. SHAFFER PQRTABLE CRANE .Filed July 31. 1922 2 Sheets-Sheet 2 INVENTOR,

Patented Dec. 18, 1928.

LAYTON S. SHAFFER, OF RAVENTVA, OHIO,

ASSIGNOR- TO THE BYERS MACHINE COM- rm, OF RAV'ENNA, OHIO, A CORPORATION OF OHIO.

PORTABLE CRANE.

Application filed July 31,

The present invention, relating, as indicated, to portable cranes and the like, 1s more particularly directed to an improved means for securing a power steering of the apparatus when the same is desired. Such machines as usually driven are either steered by hand or are connected permanently for power steering. In many cases it is necessary that the upper revolving part be placed at one particular position before the. steering mechanism is connected. Also in many cases it is necessary for the operator to leave his position to connect the steering apparatus.- One of the objects of the present invention is to provide means which are normally inoperative when traveling, and which may be connected to the driven traction devices for "steering the vehicle and which may be made by operator from his position on the vehicle. To the accomplishment' of the foregoing and related ends, said invention, then, consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawings and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings Fig. 1 is a plan view of my improved ma chine; and Fig. 2is a side elevation of the same.

The machine consists of a frame 1 which is supported by tract-ion devices which may be in the form of continuous track-laying treads 2. These are illustrated in the present drawings and are of the usual type, consisting of connected links 3 operated over sprockets 4, the sprockets being mounted in a sub-frame 5 fixed to the main frame 1.

Pivotally mounted on the main frame 1 is a turntable 6, on which are carried the usual power plant 7 and driving shaft 8. The boom and the operating mechanism therefor are of the usual type and are not shown on the present drawings.

On the turntable 6 there is mounted a de pressible rod 10 connected at its lower end to a lever 11, which operates an engaging pin 12. This engaging pin is mounted in suitable guides and is normally held in its upper or inoperative position by a spring 13. When the rod 10 is depressed it moves the engaging pin 12 downward into one of a series 1922. Serial No. 578,645.

of holes let formed in a large gear 15, which r is mounted about a vertical axis. This gear 15 is mounted wlthm a track 16 on the frame 1, on whichthe turntable rotates, the latter being supported by rollers 17. i

The gear 15 operates a small pinion 20 on a shaft 21, and on the lower end of this shaft 20 isa bevel gear 22 operating a second bevel gear 23, which drives a transverse shaft 24.. Wrapped around the shaft 24 are two chains or other flexible means 25 and 26, thesefiexible members being wrapped around the shaft in opposite directions sothat one is wound up as the other unwinds. Each of are held in that condition by springs 33. On

the outerends of the shaft 32 are sprockets 34, over which there pass chains 35 which engage'and drive sprockets 36 attached to the sprockets 4 for operating the continuous treads. The connections between the engine and the driving shaft 32 are of the usual type and need not be described in detail, as the present invention is concerned only with the means for steering the crane.

The operation of the device is as follows When it is desired to turn the crane the rod 10 is depressed, engaging the pin 12 with the gear 15. The turntable is then turned toward the side that it is desired to turn the machine toward with the following result. The larger gear 15 is swung with the turntable through the medium of the'pin 12, thus operating the shaft 21 and rotating the shaft 24. Depending upon the direction of rotation of thisshaft, either the chain 25 or 26 is wound about the shaft and swings the bell crank lever 28 toward the shaft, thus pulling out the clutch 31. As the clutch is released the drive from the shaft 32 to that side of the machine and to the corresponding tread is disconnected, and further movement of the bell crank brings a projection 40 on the arm 28 of theb-ell crank lever into the path of movement of a series of projecting lugs 4 1 on the outer member of the clutch 31. This locks the clutch 31 and the tread which is ordinarily driven thereby against further movement and permits the machine to be swung about that tread as a pivot as the other" tread continues its operation. By bringing the turntable to one side or the other While continuing the drive to the treads the machine can be turned to either side, and this steering is effected entirely by engine power without requiring any other operation by the operator than the depression of the pedal 10.

The present mechanism provides a simple and strong means for securing a power operated steering of large port-able cranes and the,

like without the additional complication which is necessary when the steering means are permanently connected to the source of power, and which may be ope 'ated from any position of the upper unit, that is, the boom and turntable.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated means be employed.

I therefore particularly point out and distinctly claim as my invention 1. In a machine of the character described, a combination of a frame, t'action devices, supporting the same, a turntable pivotally mounted on said frame, separate means for driving, each of said traction devices, a power shaft having normally engaged connections with each said driving means, a gear mount ed adjacent said turntable about its pixotal axis, said gear having a series of circularly arranged holes formed therein, a manually operated pin carried by said tin-ntable adapted to be received in one of said holes to connect said gear to the turntable, and connections between said gear and said normally engaged connections adapted to selectively disconnect the latter upon rotation of the gear.

2. In a machine of the character described, the combination of a frame. traction devices supporting the same, a turntable pivotally mounted on said frame, separate means for driving each of said traction devices, means operable by said turntable adapted to disconnect one of said driving means from the device normally driven thereby irrespective of the position of said turntable, and means including a pivoted bell-c'ank having one arm thereof outwardly connected to said disconnecting means, and the other arm thereof actuated by said disconnecting means and adapted to lock the disconnected traction device against movement simultaneously with such disconnecting means.

Signed by me this 4th day of May, 1922.

LAYT ON S. SHAF F ER. 

